Method and apparatus for drilling holes



' Oct. 2s, 192s. 1,688,994 E. SMITH f METHOD AND APPARATUS FOR DRILLING HOLES Filed Deo. 17, 1923; 2 Sheets-Sheet l BY 79g M/ gi-.

f L ATTORNEYS Oct. 23, 1928.

1,688,994 E. sMxTH METHOD AND APPARATUS FOR DRILLING HOLES Filed Dec. 17, 1925 2 Sheets-Sheet 2 VAYA/@YA /f y A@ www my my mwN/ a@ lNvENTpR Patent 0d. 2id, lQZ.

ra-aan EGG-LESTON SMITH, 0F SIOUX CITY, IOWA, SSTC-KNOB TO EGGLESTON DBILLING COE- PORATION, OIE' DOVER, DELAWARE, A CORPORATION OF DELAWARE.

METHOD AN D APPARATUS FOB DRILLING HOLES.

Application led December 17, 1923 l Serialv En. 681,032.

The present invention relates to methods and apparatus for drilling holes, and has for its object the provision of an improved method and apparatus for drilling holes.

The drilling of holes in the earth, for example, when boring for oil, gas, water, or minerals, presents many diiliculties, and for carrying on such drilling operations two systems of drilling are in common use. In one of these systems the material which is being drilled through is cut or losened by the impact of a suitable tool with the bottom of the hole, the tool being, in this system, actuated-by a reciprocating motion which is imparted to the tool b appropriate apparatus at the surface of t e ground. The other of these systems is known as the rotary system.

The present invention relates particularly to the latter system of drilling. In this system a motion of rotation is employed to cause the tool to cut its way through the material to be drilled. This rotary motion is usually imparted to the drilling tool by 'means of a drill shaft which extends to the surface of the ground where suitable apparatus is provided for rotating the shaft and for occasionally hoistingthe tool to the surface for examination. The drill shaft is commonly in the form of a pipe through which mud-laden water is forced under sufficient pressure tol clear and carry away the cuttings from the tool and force them up around the outside of the drill shaft to the surface of the ground. This system of drilling include such methods as the rotary, the calyx, the diamond, and4 the adamantine which are well known in the art under these names. p

In well drilling of this character the `great majority of the drilling must be done at several hundred, or-even several thousand feet, below the surface of the ground where the operator of the drill is stationed. It

, is thus extremely difficult for the operator to learn the conditions under which his drilling tool is operating, the characteristics of the sand, clay, or rock `which the drill is en^ountering, and the effectiveness with which the drill is working its way through this material. In all drilling operations`the rate at which the drill is fed into the material is of great importance, but urfler these conditions, the importance of the proper rate of feed is accentuated.

which-is entrusted to their hands.

The rate of yfeed of the drilling tool dev pends upon the feeding pressure employed, and too great a feeding pressure results in an excessive depth of cut by the drilling tool which, when drilling through relatively soft material, almost inevitably results in the tool becoming encased in a mass of unground material from the bottom of the hole which clings to the surface vof the tool and completely stops its progress. This is known 'as balling up, and Whenever it Qceurs, a great amount of time' is lostin"spud ding, washing away, or otherwise clear'- ing the material from the tool so as to allow it to cut. When. drilling through relatively hard material, too great a feeding pressure not infrequently causes the jamming and breakage of the tool.

4 `When diamond cutting tools are used, too..-v

great a feeding pressure often unseats the diamonds and they are lostv in the hole. Too small a feeding pressure, of course, results in slow progress of the-,drilling operations. At present it is customary to depend almost entirely upon the skill of the well driller to regulate the feeding pressure and these operators are not infrequently less skilled than they should be when proper regard is taken of the amount of capital In accordance with the method of the present invention, the feed of the rotary drilling tool is regulated by holding the tool against the material to be drilled by a feeding pressure which varie: in inverse relation to the resistance to rotation encountered by the drilling tool, that is, the feeding pressure decreases as the resistance to rotation inc. eases, and, conversely, the feeding pressure increases as the resistance to rotation decreases. In carrying out the invention the drilling tool is rotated in contact with the material to be drilled'under a predetermined normal or uniform feedingV pressure, and a force is simultaneously applied to the drilling tool in opposition to the predetermined normal feeding pressure which varies in relation to the resist-ance to rotatie. that is, this opposing force increases as the resistance to rotation increases. The resultant of these two forces, that is,

`the predetermined normal feeding pressure and the vopposing force, produces a re,- sulting actual feeding pressure which Var1es in relation to the resistance to rotation`l im lul l being less as the resistancev to rotation in' creases, and greater as the resistance diminishes.

. By applying a predetermined normal feed lng pressure, vthe amount of feeding pres-.

' sure which'may be exerted `upon the tool is limited, and by applying the opposing variable force, the actual feeding pressure which .urges the tool towardv the material to be drilled is caused to vary according to the character of this material. Thus, when the drilling tool is operating upon a hard substance, such as rock, for example, the actual feeding pressure will be automatically reduced in value in relation to the resistance to rotation which such hard substance exerts against'the cutting teeth of the drill. If, on the other hand, the tool is working in relatively s oft material, such as shale or sand, the resistance to rotation may not be as great and the feeding pressure will consequently be automatically increased. Again, v

when the drilling tool is operating upon either hard or soft material and its teeth come into engagement with substances that are relatively harder than the material through which the drill has been cutting and which might tend to stall or break the drill, the resistance `to rotation imparted to the "drill by such relatively hard substance will cause the drill automatically to be withdrawn or back awa from the material. It will thus take a epth of cut sufficiently small for it to negotiate.

In drilling holes downwardly, I prefer to make use of the weight of theA drilling tool and its associated parts to supply the predetermined normal feeding pressue. In drilling holes horizontally, or inclined, as in coal mining, for example, this pressure may be applied by a suitable resilient means Such as a'spring. Such resilient means may,

lof course, be employed in drilling downwardly directed holes if it is found desirable. The force which is applied in opposition to the predetermined normal feeding pressure is derived from the rotation of the shaft which operates the drill and is applied to the 'tool by means of va suitably constructed dlevce bywhch the drill is connected to the s a t.

"The apparatus which I have provided for carrying out my improved method thus comprises a drilling tool, suitable means for applying the predetermined normal feeding pressure to the tool, which ma be leither the force of gravitation, a resilient device, or both, a rotatably driven shaft for operating the drill, and means for connecting the drilling tool to the shaft so as to rotate the tool and simultaneously therewith im- .part a force in opposition to the predetermined normal feeding pressure, this force varying in relation to the resistance to rotation encountered by the drilling tool.

two co-,operating members are used, one of which is secured to the drill shaft. The

drilling tool is operatively associated with the other -member andthe two cooperating members are provided with coacting inclined surfaces by which the rotation of one of these cooperating `members is imparted to the other.

In order that the invention maybe more fully understood, reference is vmade .t'o the accompanying drawings illustrating mechanical embodiments of the inventive idea. These drawings, however, are intended to assist in the description of the invention and not define the limits thereof. In these drawingsl Fig. 1 is a view, partly in elevation and partly in section, of a well and derriclr, including the improved well drilling apparatus for carrying out the method of the invention; y

Fig. 2 is a. view in longitudinal section of the improved apparatus by which the drilling tool is connected to the drill shaft; and' Fig. 8 is a view in longitudinal section of a similar device for use in drilling holes which are not downwardly directed.

Referring to the accompanying drawings, there is here shown a derrickv 10 erected above the well, the bore 11.of which has been drilled to some considerable depthbelow the surface of the ground. The improved drilling apparatus of the invention is attached to the lower end of the drill shaft 12 which iscoinmonly in the form of a pipe several inches in diameter joined together inv sections of standard length, additional sections being added to the drill pipe as the depth of the well increases. This drill shaft 12 extends from the bottoni of the well substantially to the surface of the ground where it is attached to the lower end of a grief stem 13 of the drill driving apparatus.

In this drill driving apparatus there is provided the usual rotating table 14 which is adapted to drive the grief stem 13 by a rotating movement, the grief stem passing through the center of the rotating table 14 and the connection between the two parts being such as to cause the grief stem to be positively rotated by the rotating table, but at the same time permit of free longitudinal motion of the grief stem with respect to the table. Rotating table 14 is driven b v a suitable source of power, such as the engine 15, by means of the power transmission and control mechanism comprising the chain 16, counter shaft 17 chain 18, clutch mechanism 19, and the gearing 20.

Attached to the upper end of the grief stem 13 is the hydraulic swivel 21 by means of which the weight of the grief stem and the control of lever 27.` Power for drivingl this hoist drum is received from the counter shaft 17. p

Also attached to the hydraulic rotary swivel 21 is the reinforced hose 28 which is connected through the pipe 29 with a pump 30 through the agency of which mud-laden liquid is forced through the drill pipe 12 to the bottom of the hole, whence it returns through the annular channel 31 outside the drill pipe 12, carrying the drillings to the surface and helping to support the walls of the hole.

By means of a sliding joint between the rotating table 14 and the grief stem 13, longitudinal motion of the grief stem and its attached drive pipe l2 and the drilling apparatus at the lower end thereof, is possible at any time and independent ofthe rotation of the table 14. The desired motion to be imparted to the drill pipe 12 is obtained by proper manipulation ofthecontrol clutch 19 and hoist lever 27'. In this manner the drill shaft 12 may be .rotated to drill the bore i or the rotation may be stopped and the drilling apparatus raised up or down, and, if desired, the block 22 may be caused to support more or less of the weight of the drill shaft 12. This is a-common way of manually regulating the amount of feeding pressure exerted upon the drilling tool.

The improved drilling apparatus of theinvention is attached at the lower end of drill shaft 12, and comprises an appropriate drilling tool orbit 32 and the automatic feed mechanism 33 for connecting the tool to the drill pipe 12.

Referring now to Fig. 2 of the accompanying drawings, the automatic feeding device comprises the two co-operating members`34 and 35. Member 34 is securely attached to the drill shaft 12 by means of an appropriate collar 36 so that the drill shaft which is set in motion by the driving apparatus at the surface of the ground will cause the member 34 to revolve.

The member 34 is provided with a helical groove 37 on its inner surface in which travels a helical rib 38 on the other cooperat-v ing member 35, which in turn fits slidably in the member 34 and is free to rotate and `to move longitudinally therein under the control of the coacting helical rib and groove. The -member 34 is suiciently thick to permit of the providingof a shoulder 39 at its upper end which extends inwardly beyond the interior wall 40 of the drill pipe 12, and on the upper end of member 35, and preffeeding pressure whic erably integral therewith, lthere is provided an enlarfed head 41 which cooperates with the shoulder 39 to prevent the member 35 from sliding out of and becoming separated from the vmember 34 when in operation. The diameter of the head 41 is such as" to permit a generouscle'arance with the interior wall 40 of the drill pipe and to allow the headv to slide freely within this pipe. u

At the vlower end of the member 35 there is secured an enlarged part 42 upon which the drilling tool 32 is mounted, as, for eX- ample, by means of the screw threads 43. The part 42 may also be threaded upon the member 35 but it is preferable to key it thereto as well. The upper surface of part 42 provides a shoulder 44 which contacts with the bottom end 45 of member 34 when 'the cooperating members are in contracted position. a

The .drilling tool or bit 32 is preferably hollow as indicated by dotted lines 46, for

dip, composition, properties, oil or mineral contents, correlation, and other information of value. gitudinal internal passageway 47 extending therethrough which terminates at its upper end in a conical entrance 48 to direct tools which may be introduced lfor fishing, corecatching, or the like.

In the operation of the improved drilling apparatus the automatic feeding device is provided at its lower end with any suitable bit 32, but preferably one which isfsuited to cut or abrade rather than one which is suited to crush. The drilling apparatus is then inserted inthe usual manner in the hole until the bit contacts with the bottom of the bole, when forward motion of the bit, and consequently of Vthe lower or driven member 35, will be arrested. The drive pipe 12 is then slowly lowered and at the Asame time allowed to slowly rotate until the lower shoulder 45 ofthe upper member 34 which is the driving member of the feeding then held against longitudinal motion 'and is caused to revolve'in the usual manner by the driving apparatusat the surface of the ground previously described. The bit 32 is heldin Contact with the surface to be cut by a force F-O which is created by the weight of the bit and the driven member This force is the redetermined normal ii would act upon the bit if it were not for the effect of the helical drivingl groove 37 and rib '38 in causing the rotation of the tool.

Because of the inclination of the cooperating helical surfaces, the force of rotation imparted by the driving vmember 34 to the Hence, the member 35 has a lon-- lli' 4 the opposite direction to the force O-L and is always. ot' a predetermined value, thc resultant actual feeding ncssure upon the bit will vary as a function of the resistance to the tool; being less asthe resistance to rotation increases, and greater as the resistance diminishes,

During the rotation ofthe driving member 34, the driving force or moment of rotation imparted to the driven member 35 will cause itfto rotate: at the same rate of speed as the driving member as long' as the resistance to rotation, that is, the moment of reaction against the teeth of the bit, is equal to the driving moment.. Vhen the resistance to rota-tion increases the driving moment imparted to the driven member is no1 sufficient to keep it rotating at the same speed and the driving moment then causes the longitudinal force L through the medium of the inclined planes, that is, the cooperating helical surfaces, to retract or lift the driven member, together with the drilling tool or bit 32. This retraction automatically lessons the bite of the driven member and reduces the resistance to rotation until it equals the rotational force or driving moment imparted to the driven member, when rotation of the driven member will then be resumed at t-he same rate of speed, that is, at the same angular velocit as that at which the driving member 34 is being rotated.

Wvhen the resistance to rotation decreases the `rotational force or -driving moment received by the driven member causes the driven member 35 to advance or extend itself from the driving member 34 under the control of the cooperating helical surfaces 37 and 38 until a resistance to rotation is developed which is equal to the driving moment, When equilibrium will be again established. In this manner the depth of cut will be automatically regulated by the feeding device and the drill shaft needs` only to be fed out from time to time by lowering the grief stem 13 to prevent the shoulder 39 and head 41 from coming into engagementl and preventing the operation of the tool. or` in other words, to keep the automatic feeding Adevice operating within its range of movement.

The modification of the apparatus shown in Fig. 3 of the accompanying drawings is intended for drilling operations which are Lacasse e directed at such an angle that the gravitational force cannot *,lieemployed entirely to produce the predetermined normal feeding pressure. In this modification the cooperating driving and driven members 34 and 35 are provided respectively with the helical groove 3T and rib V38, andthe drilling orv cutting tool 32 is mounted. upon the outer end of the driven member 35 in a similar 'manner asthat indicated in the device sho'ivn in Fig. 2.

The driving member 34 is extended in carry out. Thus, for example, it may be the drill shaft of a hole cutting machine which is frequently operated in the vertical, or at least in an upward position. The tool 32 and driven member 35, may also be provided with a central passageway 47 for obtaining a core, and in this event the collar 50 will have a central opening Athrough it which is provided with a conical recess 48 to facilitate the introduction of tools for fishing, fore-catching, or the like.

The-operation of the modified construction of t e improved drilling apparatus will be understood fromthe previous description of the apparatus illustrated in Fig. 2, inasmuch as the operations are similar in every respect except that the predetermined normal feeding pressure is produced by the spring 49, either in conjunction with or in opposition to the gravitational force act-` ing upon the drilling tool 32', and the driven member 35. Inasmueh, however, as this predetermined normal feeding ressure is produced by a spring instead of y gravity, this pressure will vary throughout the range of movement of the cooperating members 34 and 35 instead of being constant throughout this range of movement, as is the case With the apparatus described in Fig. 2.

By employing the improved drilling apparatus of the present invention it is possible to entirely eliminate the personal equation of the Well driller in regulating the feeding pressure to be applied to the. drilling tool, inasmuch as the control of this pressure is entirely taken out of his hands. A predetermined normal feeding pressure is first applied and then a force acting in opposition to this pressure which is derived from the rotating driving movement of the Htl ance to rotation of and plowing action, instead of by a crushing action, may be advantageously used in the method and with the improved feeding device of the invention. Also, by virtue of the relatively accurate adjustment of the compressive and torsional forces acting upon the bit, particular forms of cutting or abrading tools which willpulverize the entire material cut through as the bit advances may be used, and in this way the drilling water is allowed to carry away immediately all of the cuttings and substantially eliminates the operation known as spud'ding which not infrequently occupies as much as 50% of the drilling time. Furthermore, the ability to utilize efficient drilling tools which cut away the material greatly reduces the amount of power required to operate the drilling apparatus by doing away with the excessive friction between the end of the bitand the bottom of the bore hole, which in many types of bits results ina relatively small amount of actual drilling. e

Moreover the'present invention does away with the necessity of attempting to regulate the feeding pressure on the driliing bit by the use of sliding sleeves, weight-regulating devices located at the surface of the ground, or by other means.

Although the invention has been described with particular reference to earth boring for oil, gas, water, or minerals, it may also be employed to advantage in constructing aeration, power transmission, plunger shafts, and the like, and the invention may also be used in drilling, reaming, or cleaning holes' in other substances, such, for example, as wood or metal. 1

I claim:

1. A rotary drilling apparatus comprising, a drilling tool, means for applying a predetermined normal feeding pressure to said tool, a rotatably driven drill shaft, and means for connecting said drilling tool to said shaft including means for continuously impartin in opposition to the predetermined normal eeding pressure a force which becomes larger or smaller respectively as the resistance to rotation encountered by the drilling tool increases or decreases.

2. A 4rotary drilling apparatus comprising, a drilling tool, a rotatably driven drilll shaft, means for applying a predetermined force tending to hold said tool in contact with the material to 'be drilledand meansv associated with said drill shaft and said tool for continuously imparting a rotational force to the tool andlfor4 changing the direction of the force of resistance to'rotation to a Aforce of retraction tending to withdraw the tool from the material to be drilled.

3. A rotary drilling appara-tus comprising, a drilling tool, a rotatably driven drill shaft, means for applying a predetermined force tending to hold said tool in Contact with the material to be drilled and means interposed between said drill shaft and said tool for simultaneously imparting to said tool a force of rotation and for chan ing the force of resistance to rotation to a orce in opposition to said predetermined force.

4. A rotary drilling apparatus comprising, a rotatable driving member, a driven member operatively associated therewith, a drilling tool operatively associated with said driven member, means for applying a predetermined feeding pressure to said drilling tool, and means for connect-ing said driving member with said driven member so as to impart rotation thereto and simultaneously and continuously therewith to change the direction of the-'force of resistance to rotatation to a longitudinally directed force exerted in opposition to said feeding pressure,

said connecting means also allowing Aof longitudinal movement between said driving and said driven members vto allow the drilling tool to advance with respect to the driving member as the,hole is cut.

5. A feeding device for rotary drilling tools or the like comprising, a rotatable driving member, a driven member associated therewith and to which said tool is operatively connected, means for applying a predetermined feeding pressure to said tool, and means for connecting said driving .member With said driven member comprising coacting helical surfaces, whereby said tool is retracted when the resistance to rotation exceeds a predetermined amount.

6. A feeding devicevfor rotarydrilling tools or the like comprising, a rotatable driving member, a driven member associated therewith and to which the drilling tool is operatively connected, means for applying a predetermined feeding pressure to said tool, and means for connecting said driving tools or the like comprising cooperating 5. bers to shift coac'tingl 10 motion 1s imparted from the driving member rotatingdriving and driven members, a drilling tool operatlvely connected vto the driven to the driven member and which produce a 'tudinally acting force in opposition to predetermined feeding pressure, the resultant of said feeding pressure and said `1.5 force imparting avarying drilling pressure to the tool.

1,ese,994

8. A 'rotary drilling'apparatus comprising a drilling tool, means for applying acluding means for converting the direction of the force of resistance to rotation encountered by the drilling tool to a longitudinally directed force opposed to said predetermined pressure, the resultant of said predetermined sressure and said opposing vforce proucing a varying feeding pressure upon the drilling tool. Y

In testimony whereof I afiix my signature.

EGGLESTON SMITH. 

